Working LALRPOP grammar for the lambda calculus

lambda.lalrpop

use ::Expr;
use ::app_chain;

grammar;

pub Expr = {
    <Fun>,
    <App>,
    <Prim>,
};

Fun: Box<Expr> = {
    "/" <Id> "." <Expr> => Box::new(Expr::Fun(<>)),
};

App: Box<Expr> = {
    <Prim+> <Prim> => app_chain(<>),
    <Prim+> <Fun> => app_chain(<>),
};

Prim = {
    <Var>,
    "(" <Expr> ")",
}

Var: Box<Expr> = <Id> => Box::new(Expr::Var(<>));
Id: String = <r"[a-zA-Z_][a-zA-Z0-9_]*"> => <>.to_owned();